192 Veterinary Medicine. 



left in the filter is most virulent, and must be thoroughly steri- 

 lized to obviate dangers from its dissemination. 



3d. Intravenous injection of a small quantity of virus, con- 

 taining but a few bacilli produces no local swelling, but only a 

 slight temporary hyperthermia and permanent immunity. The 

 greatest care is necessary in the manipulation, to prevent any 

 contact of the bacillus with the subcutaneous tissues or the walls 

 of the vein. The virulent exudate swarming with bacilli is taken 

 and a drop or two added to a normal salt solution, which is di- 

 luted and shaken in a stoppered bottle, until each drop contains 

 but one, or at most two bacilli. Then the hands having been 

 thoroughly washed with soap and warm water and rinsed in a 5 

 per cent, solution of carbolic acid, and the instruments having 

 been boiled, the vein is raised as for bleeding, and penetrated by 

 a short cannula and trochar, which after boiling has been dipped 

 in the carbolic acid solution, the trochar is withdrawn, and the 

 nozzle of the syringe containing the virulent solution is inserted 

 through the cannula, so that its point is free in the centre of the 

 blood stream, into which a few drops of the virulent solution are 

 discharged. The nozzle is left in place for a few seconds to ensure 

 the washing of any infecting matter from its point, when it is 

 withdrawn, followed immediately after by the cannula. Great 

 care should be taken to avoid any scratching of the inner coat of 

 the vein with the cannula, trochar or nozzle. 



4th. Another method of immunizing is by the injection of the 

 virulent liquid into the trachea and bronchia. This appears to 

 bring it so directly in contact with the blood, that the microbes 

 are destroyed as rapidly as if it were introduced into the blood 

 stream direct. The injection is made between two tracheal rings, 

 the manipulation being essentially the same as in the cases of the 

 vein, the tissues being first perforated by a sterilized cannula and 

 trochar, and the sterilized nozzle subsequently inserted through 

 the cannula. 



5th. Inoculation into the tip of the tail can be successfully em- 

 ployed, the coldness of the region and the scantiness of the con- 

 nective tissue preventing any dangerous increase of the bacilli in 

 the cooler season. In the heat of summer, however, this is to be 

 avoided as dangerous. The tail is first washed with soap and 

 water followed by a 3 per cent solution of phenol. It is then 



